/*****************************************************************************/
/*                                                                           */
/*                                tgttrans.c                                 */
/*                                                                           */
/*                         Character set translation                         */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 2000-2012, Ullrich von Bassewitz                                      */
/*                Roemerstrasse 52                                           */
/*                D-70794 Filderstadt                                        */
/* EMail:         uz@cc65.org                                                */
/*                                                                           */
/*                                                                           */
/* This software is provided 'as-is', without any expressed or implied       */
/* warranty.  In no event will the authors be held liable for any damages    */
/* arising from the use of this software.                                    */
/*                                                                           */
/* Permission is granted to anyone to use this software for any purpose,     */
/* including commercial applications, and to alter it and redistribute it    */
/* freely, subject to the following restrictions:                            */
/*                                                                           */
/* 1. The origin of this software must not be misrepresented; you must not   */
/*    claim that you wrote the original software. If you use this software   */
/*    in a product, an acknowledgment in the product documentation would be  */
/*    appreciated but is not required.                                       */
/* 2. Altered source versions must be plainly marked as such, and must not   */
/*    be misrepresented as being the original software.                      */
/* 3. This notice may not be removed or altered from any source              */
/*    distribution.                                                          */
/*                                                                           */
/*****************************************************************************/



#include <string.h>

/* common */
#include "check.h"
#include "target.h"
#include "tgttrans.h"
#include "coll.h"
#include "xmalloc.h"



/*****************************************************************************/
/*                                   Data                                    */
/*****************************************************************************/



/* Translation table actually used. Default is no translation */
static unsigned char Tab[256] = {
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
    0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
    0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
    0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
    0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,
    0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,
    0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
    0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
    0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
    0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
    0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,
    0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
    0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,
    0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
    0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
    0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF,
};

#define MAX_CHARMAP_STACK   16
static Collection CharmapStack = STATIC_COLLECTION_INITIALIZER;



/*****************************************************************************/
/*                                   Code                                    */
/*****************************************************************************/



void TgtTranslateInit (void)
/* Initialize the translation tables */
{
    /* Copy the translation for the selected target */
    memcpy (Tab, GetTargetProperties (Target)->CharMap, sizeof (Tab));
}



int TgtTranslateChar (int C)
/* Translate one character from the source character set into the target
** system character set.
*/
{
    /* Translate */
    return Tab[C & 0xFF];
}



void TgtTranslateBuf (void* Buf, unsigned Len)
/* Translate a buffer of the given length from the source character set into
** the target system character set.
*/
{
    /* Translate */
    unsigned char* B = (unsigned char*)Buf;
    while (Len--) {
        *B = Tab[*B];
        ++B;
    }
}



void TgtTranslateStrBuf (StrBuf* Buf)
/* Translate a string buffer from the source character set into the target
** system character set.
*/
{
    TgtTranslateBuf (SB_GetBuf (Buf), SB_GetLen (Buf));
}



void TgtTranslateSet (unsigned Index, unsigned char C)
/* Set the translation code for the given character */
{
    CHECK (Index < sizeof (Tab));
    Tab[Index] = C;
}



int TgtTranslatePush (void)
/* Pushes the current translation table to the internal stack
** Returns 1 on success, 0 on stack full
*/
{
    unsigned char* TempTab;

    if (CollCount (&CharmapStack) >= MAX_CHARMAP_STACK) {
        return 0;
    }

    TempTab = xmalloc (sizeof (Tab));
    memcpy (TempTab, Tab, sizeof (Tab));

    CollAppend (&CharmapStack, TempTab);
    return 1;
}



int TgtTranslatePop (void)
/* Pops a translation table from the internal stack into the current table
** Returns 1 on success, 0 on stack empty
*/
{
    unsigned char* TempTab;

    if (CollCount (&CharmapStack) == 0) {
        return 0;
    }

    TempTab = CollPop (&CharmapStack);

    memcpy (Tab, TempTab, sizeof (Tab));

    xfree (TempTab);
    return 1;
}



int TgtTranslateStackIsEmpty (void)
/* Returns 1 if the internal stack is empty */
{
    return CollCount (&CharmapStack) == 0;
}
